An unexpected pregnancy is certainly a surprise. But finding out you’re pregnant with twins halfway through the pregnancy takes “surprise” to an entirely new level.

That’s exactly what happened when Orrville residents Sarah and Bill Thistlethwaite were receiving their 19-week ultrasound on January 27, 2014 (ironically, their son Jaxon’s first birthday). “The ultrasound tech told us there were two,” recalls math teacher Sarah, 32. “My husband said, ‘Two what? Arms? Legs?’” To which the tech replied, “Two babies.” As one can imagine, that statement was followed by stunned silence, then laughter.

But these weren’t just any twins. They were two babies in one amniotic sac: monoamniotic twins. Monoamniotic twins, or mono mono twins, account for approximately one in 10,000 U.S. twin pregnancies. Mono mono twins develop from a single egg/sperm combination that splits into two, and they share one amniotic sac and placenta. Therefore, mono mono twins are always identical. And high-risk, due to the chance of cord entanglement and compression as the babies grow and move more.

Mono mono pregnancies require close monitoring. At 25 weeks, Sarah was admitted to Akron General for continual monitoring until the delivery of the twins. Bill, 36, easily took on the task of full-time dad to Jaxon. Sarah’s two-room suite at Akron General was well equipped with toys for Jaxon’s visits, and the trio were regularly seen walking the halls and in the outdoor courtyard. “It was the only time I was able to take off the monitors,” explained Sarah. “It was just too risky to not be monitoring the twins at almost all times.”

Sarah spent 57 days on bed rest before the girls were born via scheduled c-section 45 seconds apart on May 9, 2014, at Akron General. The girls had just passed the 33-week mark.

In true Thistlethwaite style, the surprises continued. When Akron Children’s Neonatologists Dr. Melissa Mancuso and Dr. Katherine Wolfe held Jenna and Jillian up above the draped barrier to debut the little ones to Sarah and Bill, the girls reached for each other and grasped hands, then embraced arms. Sarah giggled and summed up the magical moment: “They are best friends already.” Jenna was born weighing 4 pounds 3 ounces; Jillian weighed 3 pounds 13 ounces.

The twins spent the first night in the Akron Children’s Special Care Nursery at Akron General and were transferred to Akron Children’s NICU the following day for breathing assistance. Sarah was released from Akron General on May 13, Day 61 of her stay at Akron General.

“Everyone became my family; not just the nurses and doctors, but the housekeepers and dietary and every familiar face I saw daily,” says Sarah. “It made an unfortunate situation okay.”

Jenna and Jillian continue to make international news for the breath-taking moment that stole hearts across the world. In the words of their mom: “It was as if they were saying, ‘We’ve got this. We’re going to be okay. We’ve got each other.’”

Second set of mono mono twins arrives less than one week later

Six days after the birth of Jenna and Jillian, Akron residents Amanda Arnold and James McCail had a smooth delivery and two healthy little girls after spending five weeks being closely monitored at Akron General.

Fraternal twins run in Amanda's family, so she wasn't totally shocked to learn that she was having two babies. However, she had never heard of a mono mono twins until she learned she was carrying them. JaNiya and Amaya McCail were born at 32 weeks and join big brother "Little James," who is age 5.